The present invention relates to compositions for personal care products. More particularly, the present invention relates to silicone compositions which achieve conditioning benefits in hair care products.
Silicones are widely used in hair care products due in part to the conditioning benefits that they impart to hair. In most applications, the silicone is deposited on hair out of a matrix but is often held only by weak physical forces, such as hydrogen bonding or van der Waals interactions. Because the interactive forces are weak, the benefits of silicone by deposition are generally short lived. Another issue with silicone conditioning agents is that conditioning benefits are often attributed to the deposition of high molecular weight, high viscosity fluids and gums that can weigh down the hair. Beneficial conditioning effects can also be caused by treating hair with silanol capped amino-functionalized silicones. These silicones can undergo condensation cure reactions on hair to form somewhat durable films.
It is widely known by those skilled in the art that covalent bonding is one key to “permanent” hair treatment. Processes which alter the structure of the hair, such as permanent wave and color treatment methods, do provide longer lasting effects. These processes include glycolate reduction and peroxide reoxidation. A significant disadvantage of these processes is that they are very damaging to hair and can only be carried out infrequently.
Gough et al. in U.S. Pat. Nos. 5,523,080 and 5,525,332 describe the synthesis of silicone-azlactone polymers which exhibit covalent bonding and “permanent” conditioning benefit. Gough et al. discuss incorporating an azlactone-functionalized copolymer which consists of vinylazlactone and methacryloyl polydimethylsiloxane monomers into a silicone-active group-hair structure. The hair treatment using the silicone-azlactone polymers does not consist of the steps of reduction with a glycolate or reoxidation with peroxide.
It is desirable to produce silicone compositions which can be used to treat damaged hair and provide durable benefits. Thus, silicone products are constantly being sought which can both covalently bond to hair as well as impart hair care benefits appreciated by consumers.